The traditional LED lamp is a very common illuminating tool which only has an illuminating function, however, an air purifier is purchased generally as a small household appliance at a high price. Moreover, most of the harmful gases, such as smog, float on the upper layer of indoor air, such that it is necessary for the traditional air purifier to spend a relatively long time to purify the whole room. Therefore, to solve said problem, an air purifying function is added to lamps by a part of manufacturers at present, however, in general cases, a fan is taken as a driving source of wind energy to suck air and then exhaust purified air. But the problems, such as dust accumulation and noise during the operation of the fan are not beneficial for maintenance, and the structure is relatively complicated.